Virtually since the invention of the telephone by Alexander Graham Bell in 1876, it has been recognized that a unique telephone number for notifying authorities of emergencies (crime, fire, injury . . . ) would be a tremendous boon to public health and safety.
Britain implemented its first emergency telephone system in 1937 using the number 999. This British system serving police, fire and Emergency Medical Service (EMS) was developed after fatal delays in phone calls reporting a fire on Wimpole Street. In 1957 the National Association of Fire Chiefs in the United States suggested a single number for reporting fires. In 1958 New Zealand instituted its 111 emergency telephone number. In 1959 the police department in Winnipeg Canada introduced North America's first emergency telephone system. President Lyndon Johnson's Commission on Law Enforcement and Administration of Justice issued a report in 1967 that recommended a single number for emergency calls that should be used nationwide.
In cooperation with AT&T (the predominant telephone carrier at that time), the designation of 911 as a universal emergency number was announced in January of 1968. The first 911 system was adopted in California in 1970. In the mid 1970s California's Alameda County launched the first 911 system that provided for selective routing of 911 calls. Prior to this pilot project, all 911 calls were routed according to “hard wired” instructions in the switching systems of the telephone companies. This original pilot program provided the county's Public Safety Answering Points (PSAPs) with the Automatic Number Identification (ANI) of the caller. This system did not provide for Automatic Location Identification (ALI) which would allow the PSAP to immediately and electronically identify the location of the originating landline telephone.
Although the selective routing of 911 calls has evolved and, for the most part, has worked very well for landline telephones, the prevalence of wireless communication devices (cell phones) presents new challenges.
The number of subscribers in the United States using wireless services grew from 55 million in 1997 to 253 million in 2007. Worldwide there are 2.3 billion wireless subscribers. 8% of the United States population uses cell phones with a volume of 2 trillion wireless minutes in 2007. 12.8% of United States households are “wireless only.” Californians alone placed 23.3 million 911 calls in 2007. Of these, 11.6 million (50%) were made from wireless devices. Current estimates are that 58% of 911 calls are wireless.
The early development, deployment, evolution and growth of the wireless technology are highly relevant to the present invention. Many, if not the majority of original cell phone towers in the United States were placed along the major highways throughout the country. Part of the reason for this placement of towers was due to the existing right of way which facilitated their placement. The primary reason for their placement along highways though, was that most of the initial deployment of cell phones was in automobiles (“car phones”).
As most emergency 911 calls from original wireless devices, car phones, originated on the highway, a completely rational decision was made to route these calls to the authority with the jurisdiction for responding to emergencies on the highways. Typically this was the Highway Patrol (e.g., California Highway Patrol (CHP) in California). For the most part, this system of routing wireless 911 calls to the Highway Patrol persists to this day. When fielding these wireless 911 calls approximately 95% are rerouted from the Highway Patrol to the appropriate PSAP that has jurisdiction over the emergency (e.g., local police department, fire department, sheriff, EMS . . . ).
As is readily appreciated, time is of the essence in many, if not most, emergency situations (e.g., a house fire). Often, a matter of minutes can literally mean the difference between life and death. As is further appreciated, the present system inherently induces a delay of the responders as the wireless 911 phone call must first be routed to the legacy entity (e.g., the Highway Patrol) and then subsequently routed to the appropriate responding PSAP.
Cell phone providers, either themselves, or through contractors, place cell phone antennas either on towers or buildings or other such structures. The cell phone service provider maintains data which indicates the physical orientation of each of the cell phone antennas (known as sectors) in its network. FIG. 1 illustrates a typical Test Validation Worksheet (TVW) 100 from a cell phone service provider. The TVW 100 purportedly describes the direction (the coverage area) of installed cell phone antennas. The TVW 100 includes an identification of the cell site 110 which includes an identification of the specific antenna 120 and provider 130 operating on that antenna. The TVW 100 also includes the Sector (antenna) azimuth 140 and the Sector Compass Orientation 150 which purport to represent the physical orientation of the antenna. Columns 160 detail the street address, city and county location of the antenna, while columns 170 list the longitude and latitude coordinates of the antenna. Finally, column 180 lists a recommended PSAP to which e-911 calls should be routed on the assumption that the antenna is oriented in the direction indicated in the TVW 100.
This TVW 100 is given to the local agencies (Public Safety Answering Points (PSAPs), California Highway patrol, county coordinators) in order for them to determine the proper jurisdiction to which emergency phone calls received from the various sectors (antennas) of the cell phone networks are routed. As the jurisdictions for the emergency responding agencies are based on geographic boundaries, the sector information (orientation and range) is critical to the proper decisions in regard to the routing of calls to the appropriate responding agency. If the sector information (orientation and range) contained in the TVW 100 is inaccurate, the local agencies erroneously decide to route 911 emergency calls to improper responding authorities.